This time last year, while Bradley Cooper was making the rounds for his Oscar-nominated lead actor turn in David O. Russell's "Silver Linings Playbook," he was also getting ready to get back in the ring with Russell for "American Hustle." The day after the Oscars, Cooper flew to Boston to begin work on the con artist comedy, in which he plays a live-wire FBI agent trying to make a name for himself with the Abscam sting operation. In a video interview, he spoke to The Envelope about his Oscar-nominated supporting role. Here are excerpts from the conversation.

How did your character evolve from when Russell started writing the script to where he ended up?

It had quite a journey. I'd say that the character in the Eric Singer scripts through to the Richie DiMaso that's on the film couldn't be more different. The main thing we wanted to do was create an antagonist who was, hopefully, going to be as colorful or be in the same world of interesting as the Irving Rosenfeld or Edith Greensly or Rosalyn characters. You know, to make him not so much of a guy that you may have seen in other movies.

One of the things we started with was making me a bit unrecognizable so there would be no connection made, and we came up with the curly hair, and that was sort of a window in. Just finding little windows, the sort of habits that he would have, helped align us. And then through that, the Louis C.K. character became very clear as his counterpoint. What we discovered was this sort of petulant child that Richie DiMaso is, this sort of guy who just desperately wants to hang out with the cool kids and also sort of wants to be a man. So he changes the way he looks — he wants to take down white-collar crime because that sort of world oppressed his family growing up, but he's not really at all equipped emotionally to deal with any of it.

Right, when you see him at home, he's holed up in the bathroom of the apartment he's sharing with his mother and he's eating a chicken wing. It's not what you would call a traditional FBI agent, is it?

That's right. He's trying to get a little distance, he's suffocated in this house, so the only salvation he has is sitting on the toilet, listening to the baseball game, eating a chicken wing — a chicken leg. And you're like, "Oh, man, how does that guy show up to work and basically talk to his superior officer and try to convince him into opening a new department of the FBI?"

How did you get that tightly curled hair?

We tried a lot of wigs, and I just looked like somebody from the Three Stooges. And then we curled the hair one day [with curlers] because, to perm it, it would've been a bit permanent if it didn't work. So we put 110 curlers in, and then I sat underneath a heat lamp for 45 minutes on each side, and then it was moved. The whole thing was three hours. And we sort of loved what it did, and we thought, "Let's not mess with it, let's just do that," but not really thinking that, "Oh, that means I'll have to do it every single day."

I remember hearing a story that you and Amy Adams started dancing while you were waiting. And David saw that and wanted to use it?

He was in a production meeting and we were in the middle of rehearsal, so we waited a half-hour for him. And there was a turntable in his office, and he had "Jeep's Blues," the Duke Ellington song, on there. We played it and just started dancing. He was watching for a while [through the door's window], and then I sat down and she was just dancing, and there, two scenes were born. Her back story, and then this Studio 54 idea, having that be one of the ways these two characters fall … he falling in love and her — hopefully you're not quite sure. Is she conning him, or maybe is it in fact something happening?

So the take-away is you have to be very careful what you're doing during your downtime?

Yeah, you might mention curls, and next thing you know you have curly hair.

I'm guessing that's one of the things, that sort of energy, that excitement, that spontaneity, that you enjoy about working with Russell?

The umbrella thing would be that I know that when I come out of this experience, I'll be a better actor. Probably I will have grown as an actor in every way, and knowing that when you're going into it gives you a sense of willingness to go as far as he wants you to go, and that's a very seductive thing for a director to feel from his actors. And it's also a very empowering thing for an actor to feel, because you really know that the sky's the limit on what the product could be at the end.

I imagine there are some challenges involved in him pushing you.

I would say none of it's easy, and I think that's why maybe not everybody makes movies like this, because it does demand that you leave your ego at the door. And some days, you know, you don't want to be open, really. But that has to go away very fast, and you have to be willing to fall on your face in front of the crew on rehearsal. You just have to really be open to the process.... That said, it's not anarchy at all. I mean, it's a very specific script and story.... He just wants you to be open to his way of telling this story.

How did the scenes with Louis C.K. develop?

There was something that happened right away with Louis and me as these characters, and I think David saw it, so we kept mining it in each scene as much as we could. And it sort of came to a head in the scene where Richie thinks that he's won and he thinks that he's the man, and he takes that out on his superior officer, and you just sort of watch this guy flail like a narcissistic infant. And that was a very sort of magical scene to be a part of — we all felt it in the room that it was kind of hilarious in its insanity, where Richie's making fun of him and impersonating him and kicking him out.